Chemical Reaction Engineering Objective Questions and Answers

358. For identical flow rate and feed composition, X plug flow reactors (PER) in series with a total volume V gives the same conversion as single

359. For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, when the __________ is the controlling resistance.

A. Film diffusion

B. Diffusion through ash layer

C. Chemical reaction

D. Either A, B or C

Discussion

360. Pick out the correct statement.

A. A lower temperature favours the reaction of lower activation energy

B. The dispersion number for a reactor/vessel is uL/D

C. The rate controlling step in a reaction involving many steps is the fastetst step

D. Pore volume and porosity of a catalyst is measured by Brunaver-Emmet-Teller (BET) technique

Discussion

361. A first order reaction A → B occurs in an isothermal porous catalyst pellet of spherical shape. If the concentration of A at the centre of the pellet is much less than at the external surface, the process is limited by

A. Diffusion within the pellet

B. Reaction

C. External mass transfer

D. None of the above

Discussion

362. The rate of a homogeneous reaction is a function of

A. Temperature and pressure only

B. Temperature and composition only

C. Pressure and composition only

D. All of the above

Discussion

363. Mean residence time is equal to the space time, when

A. The feed rate is measured at temperature and pressure in the reactor

B. The temperature, pressure and the density of reaction mixture remains constant throughout the reactor

C. There is no change in number of moles in gaseous reaction

D. All of the above

Discussion

364. In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled, then the equilibrium constant will

Chemical Reaction Engineering MCQs